FWIW, my guess is that the reason this appears to be "fixed" when dropping to a smaller pagesize is simply because you're exhausting the stack more slowly. Given that it takes a long while reproduce with juju (or, so I've been told), it does also beg the question if juju has a slow memory leak.
** Package changed: linux (Ubuntu) => gccgo-4.9 (Ubuntu) ** Changed in: gccgo-4.9 (Ubuntu) Status: Incomplete => Confirmed ** Summary changed: - gccgo compiled binaries are killed by SEGV on 64k ppc64el kernels + gccgo on ppc64el using split stacks when not supported ** Tags removed: kernel-da-key performing-bisect -- You received this bug notification because you are a member of Kernel Packages, which is subscribed to linux in Ubuntu. https://bugs.launchpad.net/bugs/1304754 Title: gccgo on ppc64el using split stacks when not supported Status in “gccgo-4.9” package in Ubuntu: Confirmed Bug description: On kernels 3.13-18 and 3.13-23 (there may be others) the kernel is killing gccgo compiled binaries [18519.444748] jujud[19277]: bad frame in setup_rt_frame: 0000000000000000 nip 0000000000000000 lr 0000000000000000 [18519.673632] init: juju-agent-ubuntu-local main process (19220) killed by SEGV signal [18519.673651] init: juju-agent-ubuntu-local main process ended, respawning In powerpc/kernel/signal_64.c: sys_rt_sigreturn is jumping to the badframe: label and executing an unconditional force_sigsegv which is delivered to the userland process. Like C++, gccgo tries to decode SIGSEGV as a nil pointer access and blame some random function that happened to be the top stack frame. Reverting to the 3.13-08 kernel appears to resolve the issue which (weakly) points the finger at the recent switch to 64k pages. To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu/+source/gccgo-4.9/+bug/1304754/+subscriptions -- Mailing list: https://launchpad.net/~kernel-packages Post to : kernel-packages@lists.launchpad.net Unsubscribe : https://launchpad.net/~kernel-packages More help : https://help.launchpad.net/ListHelp